Across the country -
from neighborhood developments and apartment complexes to public parks and
private clubs - hard courts prevail because, in general, they are easy to care
for. And while they may all look alike from above, it's the differences below
the surface that can determine what's right for your facility.

Learning the nuts and
bolts of hard-court construction is my - in fact, it's information you'll need
for your next upgrade or expansion when you are speaking with contractors or
design professionals. More important, knowing some of the fundamentals will help
you make better decisions about which pavements are appropriate for your site,
how much the court might cost and its expected durability.

Start
with a Good Foundation

Underneath the acrylic
finish found on most hard courts today either is asphalt, reinforced concrete or
post-tensioned concrete - each with its own advantages and disadvantages.
Choosing one of these three hard courts for your facility could mean either
years of trouble-free maintenance or costly repairs down the road.

Hard courts, whether
asphalt or concrete, have the same basic composition below the pavement. Each
begins with a "subgrade" of compacted ground. Topsoil and organic
matter, such as tree roots, stumps, peat or muck, must be removed, otherwise it
will decompose over time and lead to settling and cracking of the pavement
above. Then a heavy roller levels out the stable ground.

Next, for all types of
hard courts, comes a "base course," consisting of densely compacted
crushed stone. The crushed stone remains porous, which keeps the pavement from
heaving during heavy rains or winter freezing. Depending on your climate and
soil conditions, the base course is usually between 6 and 8 inches thick. Now
you're ready for the pavement.

Asphalt
Pavement Courts

Asphalt, which was
introduced to the construction industry in the middle of the last century,
technically is not the pavement itself but a gooey liquid petroleum byproduct.
This liquid is heated and mixed with crushed stones to form the pavement. For
court construction, the heated mixture is trucked to the site, dumped into a
paving machine and laid over the gravel base course.

Asphalt pavement is
usually installed in two layers. The first layer, called the "binder"
or "intermediate" layer, forms the basic structure and strength of an
asphalt pavement. The second layer, called the "topping" or
"leveling" course, is formed with smaller sized stones, giving the
surface a smooth, fine-textured appearance. The smaller stones also allow the
pavement to be graded much more accurately, giving the court its proper, though
extremely flat, slope. As the pavement layers cool, they harden or
"cure," forming what is technically called asphaltic or bituminous
concrete - in layman's terms - "blacktop." In total, an asphalt court
pavement is 3 to 5 inches thick.

Even though the asphalt
pavement becomes hard during the curing process, it nevertheless remains a
"flexible" pavement. As the court warms and cools due to seasonal
temperature changes, the asphalt actually swells and shrinks. This movement is
not detectable to the court user, but, as we'll explain further on, it is an
important part of the structure of the pavement.

Reinforced
Concrete Pavement Courts

Though less common than
asphalt, concrete, due to its makeup (portland cement, crushed stone and water)
is significantly harder than asphalt and therefore is described as a
"rigid" pavement. When used for pavements, concrete is reinforced with
wire mesh or steel bars to give it greater strength and resistance to cracking.

The perimeter of a
concrete court is laid out over the crushed stone base course with wood or steel
forms. The reinforcement is placed above the base course and a 4- to
6-inch-thick liquid concrete mixture is poured into the form. Quickly, the
surface of the concrete is then smoothed out with screeds, trowels and brooms.
Concrete is hard enough to walk on- within a day or so after pouring, but it
takes a full month for it to thoroughly cure before it can be surfaced.

As concrete warms and
cools due to seasonal or even daily temperature changes, it noticeably expands
and contracts. For this reason, a concrete court must have joints that allow for
this. Unfortunately, a reinforced concrete court requires these expansion joints
within the playing area of the court, and under extremes of cold or with
improper construction, expansion joints can widen, becoming a tripping hazard.
This, and the fact that concrete tends to develop hairline cracks, has led most
designers and contractors to abandon the use of standard reinforced concrete
courts.

Post-Tensioned
Concrete Courts

Post-tensioned concrete,
first developed in the 1950's for building foundations, has been widely used for
tennis courts for more than 20 years. Today, it is the preferred concrete-court
construction technique.

Post-tensioned concrete
is, in fact, a reinforced concrete pavement, but it differs in the way it is
reinforced. Instead of using wire mesh or steel bars, post-tensioned courts are
reinforced with wire cables. After concrete is poured then cured for a few days,
wire cables are tightened under thousands of pounds of pressure.

The pulling or
"tensioning" of the cables compresses the concrete, giving it greater
strength and resistance to cracking than standard reinforced concrete.
"Post-tensioning" also gives concrete so much more strength that
post-tensioned courts usually only have an expansion joint at the net line.
Multiple courts can be constructed side to side up to 180 feet in length (three
full-sized courts) before an expansion joint is required lengthwise.

The downside is that
post-tensioned courts, like standard reinforced concrete courts, still can
develop hairline cracks. However, cracking is less frequent and movement of
these cracks is less pronounced.

Cost,
Ease of Construction and Durability

Before deciding which
court type would best suit your needs, here are a few things to consider. A
completed tennis court (whether asphalt or concrete) will probably cost between
$24,000 and $50,000, depending on the surface type, style of fencing, the number
of courts being constructed and the court's location.

Asphalt

A post-tensioned
court pavement generally costs between $24,000 and $30,000. It is extremely
durable, lasting 40 years or more.

Construction
requires highly specialized workers, but post-tensioned concrete can be
dropped by bucket or pumped into place with long hoses, reaching hard-to-get
areas like wooded sites or rooftops.

Post-tensioned
concrete is able to bridge over poor, expansive soils. Expansive soils occur
throughout the U.S., but they are most prevalent in areas such as Louisiana,
Texas, Colorado, California, Idaho, Nevada and Arizona.

It is an excellent
choice if you are building a hard court over an existing clay or fast-dry
court since soft courts act like expansive soils.

It is a good choice
for the reconstruction of a cracked or deteriorated asphalt court. If you
were to repave the asphalt court, you would have to first remove or
pulverize the existing pavement to prevent cracks from radiating through.
Post-tensioned concrete can be installed right over a cracked court, saving
time and money.

Concrete is not
compatible with acrylic surfacing systems and therefore needs to be properly
primed before a surface is installed, an extra step that adds slightly to
the cost of the surfacing.

Remember, issues of
cost, durability, site engineering, ease of construction and type of surface all
go into making informed decisions about what type of hard court is right for
you. If you keep in mind these basic concepts about pavements and their design
and construction requirements, hard courts aren't really so hard after all.